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author | shmel1k <shmel1k@ydb.tech> | 2022-09-02 12:44:59 +0300 |
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committer | shmel1k <shmel1k@ydb.tech> | 2022-09-02 12:44:59 +0300 |
commit | 90d450f74722da7859d6f510a869f6c6908fd12f (patch) | |
tree | 538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/zlahqr.c | |
parent | 01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff) | |
download | ydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz |
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/zlahqr.c')
-rw-r--r-- | contrib/libs/clapack/zlahqr.c | 755 |
1 files changed, 755 insertions, 0 deletions
diff --git a/contrib/libs/clapack/zlahqr.c b/contrib/libs/clapack/zlahqr.c new file mode 100644 index 0000000000..ea4178f527 --- /dev/null +++ b/contrib/libs/clapack/zlahqr.c @@ -0,0 +1,755 @@ +/* zlahqr.f -- translated by f2c (version 20061008). + You must link the resulting object file with libf2c: + on Microsoft Windows system, link with libf2c.lib; + on Linux or Unix systems, link with .../path/to/libf2c.a -lm + or, if you install libf2c.a in a standard place, with -lf2c -lm + -- in that order, at the end of the command line, as in + cc *.o -lf2c -lm + Source for libf2c is in /netlib/f2c/libf2c.zip, e.g., + + http://www.netlib.org/f2c/libf2c.zip +*/ + +#include "f2c.h" +#include "blaswrap.h" + +/* Table of constant values */ + +static integer c__1 = 1; +static integer c__2 = 2; + +/* Subroutine */ int zlahqr_(logical *wantt, logical *wantz, integer *n, + integer *ilo, integer *ihi, doublecomplex *h__, integer *ldh, + doublecomplex *w, integer *iloz, integer *ihiz, doublecomplex *z__, + integer *ldz, integer *info) +{ + /* System generated locals */ + integer h_dim1, h_offset, z_dim1, z_offset, i__1, i__2, i__3, i__4; + doublereal d__1, d__2, d__3, d__4, d__5, d__6; + doublecomplex z__1, z__2, z__3, z__4, z__5, z__6, z__7; + + /* Builtin functions */ + double d_imag(doublecomplex *); + void d_cnjg(doublecomplex *, doublecomplex *); + double z_abs(doublecomplex *); + void z_sqrt(doublecomplex *, doublecomplex *), pow_zi(doublecomplex *, + doublecomplex *, integer *); + + /* Local variables */ + integer i__, j, k, l, m; + doublereal s; + doublecomplex t, u, v[2], x, y; + integer i1, i2; + doublecomplex t1; + doublereal t2; + doublecomplex v2; + doublereal aa, ab, ba, bb, h10; + doublecomplex h11; + doublereal h21; + doublecomplex h22, sc; + integer nh, nz; + doublereal sx; + integer jhi; + doublecomplex h11s; + integer jlo, its; + doublereal ulp; + doublecomplex sum; + doublereal tst; + doublecomplex temp; + extern /* Subroutine */ int zscal_(integer *, doublecomplex *, + doublecomplex *, integer *); + doublereal rtemp; + extern /* Subroutine */ int zcopy_(integer *, doublecomplex *, integer *, + doublecomplex *, integer *), dlabad_(doublereal *, doublereal *); + extern doublereal dlamch_(char *); + doublereal safmin, safmax; + extern /* Subroutine */ int zlarfg_(integer *, doublecomplex *, + doublecomplex *, integer *, doublecomplex *); + extern /* Double Complex */ VOID zladiv_(doublecomplex *, doublecomplex *, + doublecomplex *); + doublereal smlnum; + + +/* -- LAPACK auxiliary routine (version 3.2) -- */ +/* Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd.. */ +/* November 2006 */ + +/* .. Scalar Arguments .. */ +/* .. */ +/* .. Array Arguments .. */ +/* .. */ + +/* Purpose */ +/* ======= */ + +/* ZLAHQR is an auxiliary routine called by CHSEQR to update the */ +/* eigenvalues and Schur decomposition already computed by CHSEQR, by */ +/* dealing with the Hessenberg submatrix in rows and columns ILO to */ +/* IHI. */ + +/* Arguments */ +/* ========= */ + +/* WANTT (input) LOGICAL */ +/* = .TRUE. : the full Schur form T is required; */ +/* = .FALSE.: only eigenvalues are required. */ + +/* WANTZ (input) LOGICAL */ +/* = .TRUE. : the matrix of Schur vectors Z is required; */ +/* = .FALSE.: Schur vectors are not required. */ + +/* N (input) INTEGER */ +/* The order of the matrix H. N >= 0. */ + +/* ILO (input) INTEGER */ +/* IHI (input) INTEGER */ +/* It is assumed that H is already upper triangular in rows and */ +/* columns IHI+1:N, and that H(ILO,ILO-1) = 0 (unless ILO = 1). */ +/* ZLAHQR works primarily with the Hessenberg submatrix in rows */ +/* and columns ILO to IHI, but applies transformations to all of */ +/* H if WANTT is .TRUE.. */ +/* 1 <= ILO <= max(1,IHI); IHI <= N. */ + +/* H (input/output) COMPLEX*16 array, dimension (LDH,N) */ +/* On entry, the upper Hessenberg matrix H. */ +/* On exit, if INFO is zero and if WANTT is .TRUE., then H */ +/* is upper triangular in rows and columns ILO:IHI. If INFO */ +/* is zero and if WANTT is .FALSE., then the contents of H */ +/* are unspecified on exit. The output state of H in case */ +/* INF is positive is below under the description of INFO. */ + +/* LDH (input) INTEGER */ +/* The leading dimension of the array H. LDH >= max(1,N). */ + +/* W (output) COMPLEX*16 array, dimension (N) */ +/* The computed eigenvalues ILO to IHI are stored in the */ +/* corresponding elements of W. If WANTT is .TRUE., the */ +/* eigenvalues are stored in the same order as on the diagonal */ +/* of the Schur form returned in H, with W(i) = H(i,i). */ + +/* ILOZ (input) INTEGER */ +/* IHIZ (input) INTEGER */ +/* Specify the rows of Z to which transformations must be */ +/* applied if WANTZ is .TRUE.. */ +/* 1 <= ILOZ <= ILO; IHI <= IHIZ <= N. */ + +/* Z (input/output) COMPLEX*16 array, dimension (LDZ,N) */ +/* If WANTZ is .TRUE., on entry Z must contain the current */ +/* matrix Z of transformations accumulated by CHSEQR, and on */ +/* exit Z has been updated; transformations are applied only to */ +/* the submatrix Z(ILOZ:IHIZ,ILO:IHI). */ +/* If WANTZ is .FALSE., Z is not referenced. */ + +/* LDZ (input) INTEGER */ +/* The leading dimension of the array Z. LDZ >= max(1,N). */ + +/* INFO (output) INTEGER */ +/* = 0: successful exit */ +/* .GT. 0: if INFO = i, ZLAHQR failed to compute all the */ +/* eigenvalues ILO to IHI in a total of 30 iterations */ +/* per eigenvalue; elements i+1:ihi of W contain */ +/* those eigenvalues which have been successfully */ +/* computed. */ + +/* If INFO .GT. 0 and WANTT is .FALSE., then on exit, */ +/* the remaining unconverged eigenvalues are the */ +/* eigenvalues of the upper Hessenberg matrix */ +/* rows and columns ILO thorugh INFO of the final, */ +/* output value of H. */ + +/* If INFO .GT. 0 and WANTT is .TRUE., then on exit */ +/* (*) (initial value of H)*U = U*(final value of H) */ +/* where U is an orthognal matrix. The final */ +/* value of H is upper Hessenberg and triangular in */ +/* rows and columns INFO+1 through IHI. */ + +/* If INFO .GT. 0 and WANTZ is .TRUE., then on exit */ +/* (final value of Z) = (initial value of Z)*U */ +/* where U is the orthogonal matrix in (*) */ +/* (regardless of the value of WANTT.) */ + +/* Further Details */ +/* =============== */ + +/* 02-96 Based on modifications by */ +/* David Day, Sandia National Laboratory, USA */ + +/* 12-04 Further modifications by */ +/* Ralph Byers, University of Kansas, USA */ +/* This is a modified version of ZLAHQR from LAPACK version 3.0. */ +/* It is (1) more robust against overflow and underflow and */ +/* (2) adopts the more conservative Ahues & Tisseur stopping */ +/* criterion (LAWN 122, 1997). */ + +/* ========================================================= */ + +/* .. Parameters .. */ +/* .. */ +/* .. Local Scalars .. */ +/* .. */ +/* .. Local Arrays .. */ +/* .. */ +/* .. External Functions .. */ +/* .. */ +/* .. External Subroutines .. */ +/* .. */ +/* .. Statement Functions .. */ +/* .. */ +/* .. Intrinsic Functions .. */ +/* .. */ +/* .. Statement Function definitions .. */ +/* .. */ +/* .. Executable Statements .. */ + + /* Parameter adjustments */ + h_dim1 = *ldh; + h_offset = 1 + h_dim1; + h__ -= h_offset; + --w; + z_dim1 = *ldz; + z_offset = 1 + z_dim1; + z__ -= z_offset; + + /* Function Body */ + *info = 0; + +/* Quick return if possible */ + + if (*n == 0) { + return 0; + } + if (*ilo == *ihi) { + i__1 = *ilo; + i__2 = *ilo + *ilo * h_dim1; + w[i__1].r = h__[i__2].r, w[i__1].i = h__[i__2].i; + return 0; + } + +/* ==== clear out the trash ==== */ + i__1 = *ihi - 3; + for (j = *ilo; j <= i__1; ++j) { + i__2 = j + 2 + j * h_dim1; + h__[i__2].r = 0., h__[i__2].i = 0.; + i__2 = j + 3 + j * h_dim1; + h__[i__2].r = 0., h__[i__2].i = 0.; +/* L10: */ + } + if (*ilo <= *ihi - 2) { + i__1 = *ihi + (*ihi - 2) * h_dim1; + h__[i__1].r = 0., h__[i__1].i = 0.; + } +/* ==== ensure that subdiagonal entries are real ==== */ + if (*wantt) { + jlo = 1; + jhi = *n; + } else { + jlo = *ilo; + jhi = *ihi; + } + i__1 = *ihi; + for (i__ = *ilo + 1; i__ <= i__1; ++i__) { + if (d_imag(&h__[i__ + (i__ - 1) * h_dim1]) != 0.) { +/* ==== The following redundant normalization */ +/* . avoids problems with both gradual and */ +/* . sudden underflow in ABS(H(I,I-1)) ==== */ + i__2 = i__ + (i__ - 1) * h_dim1; + i__3 = i__ + (i__ - 1) * h_dim1; + d__3 = (d__1 = h__[i__3].r, abs(d__1)) + (d__2 = d_imag(&h__[i__ + + (i__ - 1) * h_dim1]), abs(d__2)); + z__1.r = h__[i__2].r / d__3, z__1.i = h__[i__2].i / d__3; + sc.r = z__1.r, sc.i = z__1.i; + d_cnjg(&z__2, &sc); + d__1 = z_abs(&sc); + z__1.r = z__2.r / d__1, z__1.i = z__2.i / d__1; + sc.r = z__1.r, sc.i = z__1.i; + i__2 = i__ + (i__ - 1) * h_dim1; + d__1 = z_abs(&h__[i__ + (i__ - 1) * h_dim1]); + h__[i__2].r = d__1, h__[i__2].i = 0.; + i__2 = jhi - i__ + 1; + zscal_(&i__2, &sc, &h__[i__ + i__ * h_dim1], ldh); +/* Computing MIN */ + i__3 = jhi, i__4 = i__ + 1; + i__2 = min(i__3,i__4) - jlo + 1; + d_cnjg(&z__1, &sc); + zscal_(&i__2, &z__1, &h__[jlo + i__ * h_dim1], &c__1); + if (*wantz) { + i__2 = *ihiz - *iloz + 1; + d_cnjg(&z__1, &sc); + zscal_(&i__2, &z__1, &z__[*iloz + i__ * z_dim1], &c__1); + } + } +/* L20: */ + } + + nh = *ihi - *ilo + 1; + nz = *ihiz - *iloz + 1; + +/* Set machine-dependent constants for the stopping criterion. */ + + safmin = dlamch_("SAFE MINIMUM"); + safmax = 1. / safmin; + dlabad_(&safmin, &safmax); + ulp = dlamch_("PRECISION"); + smlnum = safmin * ((doublereal) nh / ulp); + +/* I1 and I2 are the indices of the first row and last column of H */ +/* to which transformations must be applied. If eigenvalues only are */ +/* being computed, I1 and I2 are set inside the main loop. */ + + if (*wantt) { + i1 = 1; + i2 = *n; + } + +/* The main loop begins here. I is the loop index and decreases from */ +/* IHI to ILO in steps of 1. Each iteration of the loop works */ +/* with the active submatrix in rows and columns L to I. */ +/* Eigenvalues I+1 to IHI have already converged. Either L = ILO, or */ +/* H(L,L-1) is negligible so that the matrix splits. */ + + i__ = *ihi; +L30: + if (i__ < *ilo) { + goto L150; + } + +/* Perform QR iterations on rows and columns ILO to I until a */ +/* submatrix of order 1 splits off at the bottom because a */ +/* subdiagonal element has become negligible. */ + + l = *ilo; + for (its = 0; its <= 30; ++its) { + +/* Look for a single small subdiagonal element. */ + + i__1 = l + 1; + for (k = i__; k >= i__1; --k) { + i__2 = k + (k - 1) * h_dim1; + if ((d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[k + (k + - 1) * h_dim1]), abs(d__2)) <= smlnum) { + goto L50; + } + i__2 = k - 1 + (k - 1) * h_dim1; + i__3 = k + k * h_dim1; + tst = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[k - 1 + + (k - 1) * h_dim1]), abs(d__2)) + ((d__3 = h__[i__3].r, + abs(d__3)) + (d__4 = d_imag(&h__[k + k * h_dim1]), abs( + d__4))); + if (tst == 0.) { + if (k - 2 >= *ilo) { + i__2 = k - 1 + (k - 2) * h_dim1; + tst += (d__1 = h__[i__2].r, abs(d__1)); + } + if (k + 1 <= *ihi) { + i__2 = k + 1 + k * h_dim1; + tst += (d__1 = h__[i__2].r, abs(d__1)); + } + } +/* ==== The following is a conservative small subdiagonal */ +/* . deflation criterion due to Ahues & Tisseur (LAWN 122, */ +/* . 1997). It has better mathematical foundation and */ +/* . improves accuracy in some examples. ==== */ + i__2 = k + (k - 1) * h_dim1; + if ((d__1 = h__[i__2].r, abs(d__1)) <= ulp * tst) { +/* Computing MAX */ + i__2 = k + (k - 1) * h_dim1; + i__3 = k - 1 + k * h_dim1; + d__5 = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ + k + (k - 1) * h_dim1]), abs(d__2)), d__6 = (d__3 = + h__[i__3].r, abs(d__3)) + (d__4 = d_imag(&h__[k - 1 + + k * h_dim1]), abs(d__4)); + ab = max(d__5,d__6); +/* Computing MIN */ + i__2 = k + (k - 1) * h_dim1; + i__3 = k - 1 + k * h_dim1; + d__5 = (d__1 = h__[i__2].r, abs(d__1)) + (d__2 = d_imag(&h__[ + k + (k - 1) * h_dim1]), abs(d__2)), d__6 = (d__3 = + h__[i__3].r, abs(d__3)) + (d__4 = d_imag(&h__[k - 1 + + k * h_dim1]), abs(d__4)); + ba = min(d__5,d__6); + i__2 = k - 1 + (k - 1) * h_dim1; + i__3 = k + k * h_dim1; + z__2.r = h__[i__2].r - h__[i__3].r, z__2.i = h__[i__2].i - + h__[i__3].i; + z__1.r = z__2.r, z__1.i = z__2.i; +/* Computing MAX */ + i__4 = k + k * h_dim1; + d__5 = (d__1 = h__[i__4].r, abs(d__1)) + (d__2 = d_imag(&h__[ + k + k * h_dim1]), abs(d__2)), d__6 = (d__3 = z__1.r, + abs(d__3)) + (d__4 = d_imag(&z__1), abs(d__4)); + aa = max(d__5,d__6); + i__2 = k - 1 + (k - 1) * h_dim1; + i__3 = k + k * h_dim1; + z__2.r = h__[i__2].r - h__[i__3].r, z__2.i = h__[i__2].i - + h__[i__3].i; + z__1.r = z__2.r, z__1.i = z__2.i; +/* Computing MIN */ + i__4 = k + k * h_dim1; + d__5 = (d__1 = h__[i__4].r, abs(d__1)) + (d__2 = d_imag(&h__[ + k + k * h_dim1]), abs(d__2)), d__6 = (d__3 = z__1.r, + abs(d__3)) + (d__4 = d_imag(&z__1), abs(d__4)); + bb = min(d__5,d__6); + s = aa + ab; +/* Computing MAX */ + d__1 = smlnum, d__2 = ulp * (bb * (aa / s)); + if (ba * (ab / s) <= max(d__1,d__2)) { + goto L50; + } + } +/* L40: */ + } +L50: + l = k; + if (l > *ilo) { + +/* H(L,L-1) is negligible */ + + i__1 = l + (l - 1) * h_dim1; + h__[i__1].r = 0., h__[i__1].i = 0.; + } + +/* Exit from loop if a submatrix of order 1 has split off. */ + + if (l >= i__) { + goto L140; + } + +/* Now the active submatrix is in rows and columns L to I. If */ +/* eigenvalues only are being computed, only the active submatrix */ +/* need be transformed. */ + + if (! (*wantt)) { + i1 = l; + i2 = i__; + } + + if (its == 10) { + +/* Exceptional shift. */ + + i__1 = l + 1 + l * h_dim1; + s = (d__1 = h__[i__1].r, abs(d__1)) * .75; + i__1 = l + l * h_dim1; + z__1.r = s + h__[i__1].r, z__1.i = h__[i__1].i; + t.r = z__1.r, t.i = z__1.i; + } else if (its == 20) { + +/* Exceptional shift. */ + + i__1 = i__ + (i__ - 1) * h_dim1; + s = (d__1 = h__[i__1].r, abs(d__1)) * .75; + i__1 = i__ + i__ * h_dim1; + z__1.r = s + h__[i__1].r, z__1.i = h__[i__1].i; + t.r = z__1.r, t.i = z__1.i; + } else { + +/* Wilkinson's shift. */ + + i__1 = i__ + i__ * h_dim1; + t.r = h__[i__1].r, t.i = h__[i__1].i; + z_sqrt(&z__2, &h__[i__ - 1 + i__ * h_dim1]); + z_sqrt(&z__3, &h__[i__ + (i__ - 1) * h_dim1]); + z__1.r = z__2.r * z__3.r - z__2.i * z__3.i, z__1.i = z__2.r * + z__3.i + z__2.i * z__3.r; + u.r = z__1.r, u.i = z__1.i; + s = (d__1 = u.r, abs(d__1)) + (d__2 = d_imag(&u), abs(d__2)); + if (s != 0.) { + i__1 = i__ - 1 + (i__ - 1) * h_dim1; + z__2.r = h__[i__1].r - t.r, z__2.i = h__[i__1].i - t.i; + z__1.r = z__2.r * .5, z__1.i = z__2.i * .5; + x.r = z__1.r, x.i = z__1.i; + sx = (d__1 = x.r, abs(d__1)) + (d__2 = d_imag(&x), abs(d__2)); +/* Computing MAX */ + d__3 = s, d__4 = (d__1 = x.r, abs(d__1)) + (d__2 = d_imag(&x), + abs(d__2)); + s = max(d__3,d__4); + z__5.r = x.r / s, z__5.i = x.i / s; + pow_zi(&z__4, &z__5, &c__2); + z__7.r = u.r / s, z__7.i = u.i / s; + pow_zi(&z__6, &z__7, &c__2); + z__3.r = z__4.r + z__6.r, z__3.i = z__4.i + z__6.i; + z_sqrt(&z__2, &z__3); + z__1.r = s * z__2.r, z__1.i = s * z__2.i; + y.r = z__1.r, y.i = z__1.i; + if (sx > 0.) { + z__1.r = x.r / sx, z__1.i = x.i / sx; + z__2.r = x.r / sx, z__2.i = x.i / sx; + if (z__1.r * y.r + d_imag(&z__2) * d_imag(&y) < 0.) { + z__3.r = -y.r, z__3.i = -y.i; + y.r = z__3.r, y.i = z__3.i; + } + } + z__4.r = x.r + y.r, z__4.i = x.i + y.i; + zladiv_(&z__3, &u, &z__4); + z__2.r = u.r * z__3.r - u.i * z__3.i, z__2.i = u.r * z__3.i + + u.i * z__3.r; + z__1.r = t.r - z__2.r, z__1.i = t.i - z__2.i; + t.r = z__1.r, t.i = z__1.i; + } + } + +/* Look for two consecutive small subdiagonal elements. */ + + i__1 = l + 1; + for (m = i__ - 1; m >= i__1; --m) { + +/* Determine the effect of starting the single-shift QR */ +/* iteration at row M, and see if this would make H(M,M-1) */ +/* negligible. */ + + i__2 = m + m * h_dim1; + h11.r = h__[i__2].r, h11.i = h__[i__2].i; + i__2 = m + 1 + (m + 1) * h_dim1; + h22.r = h__[i__2].r, h22.i = h__[i__2].i; + z__1.r = h11.r - t.r, z__1.i = h11.i - t.i; + h11s.r = z__1.r, h11s.i = z__1.i; + i__2 = m + 1 + m * h_dim1; + h21 = h__[i__2].r; + s = (d__1 = h11s.r, abs(d__1)) + (d__2 = d_imag(&h11s), abs(d__2)) + + abs(h21); + z__1.r = h11s.r / s, z__1.i = h11s.i / s; + h11s.r = z__1.r, h11s.i = z__1.i; + h21 /= s; + v[0].r = h11s.r, v[0].i = h11s.i; + v[1].r = h21, v[1].i = 0.; + i__2 = m + (m - 1) * h_dim1; + h10 = h__[i__2].r; + if (abs(h10) * abs(h21) <= ulp * (((d__1 = h11s.r, abs(d__1)) + ( + d__2 = d_imag(&h11s), abs(d__2))) * ((d__3 = h11.r, abs( + d__3)) + (d__4 = d_imag(&h11), abs(d__4)) + ((d__5 = + h22.r, abs(d__5)) + (d__6 = d_imag(&h22), abs(d__6)))))) { + goto L70; + } +/* L60: */ + } + i__1 = l + l * h_dim1; + h11.r = h__[i__1].r, h11.i = h__[i__1].i; + i__1 = l + 1 + (l + 1) * h_dim1; + h22.r = h__[i__1].r, h22.i = h__[i__1].i; + z__1.r = h11.r - t.r, z__1.i = h11.i - t.i; + h11s.r = z__1.r, h11s.i = z__1.i; + i__1 = l + 1 + l * h_dim1; + h21 = h__[i__1].r; + s = (d__1 = h11s.r, abs(d__1)) + (d__2 = d_imag(&h11s), abs(d__2)) + + abs(h21); + z__1.r = h11s.r / s, z__1.i = h11s.i / s; + h11s.r = z__1.r, h11s.i = z__1.i; + h21 /= s; + v[0].r = h11s.r, v[0].i = h11s.i; + v[1].r = h21, v[1].i = 0.; +L70: + +/* Single-shift QR step */ + + i__1 = i__ - 1; + for (k = m; k <= i__1; ++k) { + +/* The first iteration of this loop determines a reflection G */ +/* from the vector V and applies it from left and right to H, */ +/* thus creating a nonzero bulge below the subdiagonal. */ + +/* Each subsequent iteration determines a reflection G to */ +/* restore the Hessenberg form in the (K-1)th column, and thus */ +/* chases the bulge one step toward the bottom of the active */ +/* submatrix. */ + +/* V(2) is always real before the call to ZLARFG, and hence */ +/* after the call T2 ( = T1*V(2) ) is also real. */ + + if (k > m) { + zcopy_(&c__2, &h__[k + (k - 1) * h_dim1], &c__1, v, &c__1); + } + zlarfg_(&c__2, v, &v[1], &c__1, &t1); + if (k > m) { + i__2 = k + (k - 1) * h_dim1; + h__[i__2].r = v[0].r, h__[i__2].i = v[0].i; + i__2 = k + 1 + (k - 1) * h_dim1; + h__[i__2].r = 0., h__[i__2].i = 0.; + } + v2.r = v[1].r, v2.i = v[1].i; + z__1.r = t1.r * v2.r - t1.i * v2.i, z__1.i = t1.r * v2.i + t1.i * + v2.r; + t2 = z__1.r; + +/* Apply G from the left to transform the rows of the matrix */ +/* in columns K to I2. */ + + i__2 = i2; + for (j = k; j <= i__2; ++j) { + d_cnjg(&z__3, &t1); + i__3 = k + j * h_dim1; + z__2.r = z__3.r * h__[i__3].r - z__3.i * h__[i__3].i, z__2.i = + z__3.r * h__[i__3].i + z__3.i * h__[i__3].r; + i__4 = k + 1 + j * h_dim1; + z__4.r = t2 * h__[i__4].r, z__4.i = t2 * h__[i__4].i; + z__1.r = z__2.r + z__4.r, z__1.i = z__2.i + z__4.i; + sum.r = z__1.r, sum.i = z__1.i; + i__3 = k + j * h_dim1; + i__4 = k + j * h_dim1; + z__1.r = h__[i__4].r - sum.r, z__1.i = h__[i__4].i - sum.i; + h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; + i__3 = k + 1 + j * h_dim1; + i__4 = k + 1 + j * h_dim1; + z__2.r = sum.r * v2.r - sum.i * v2.i, z__2.i = sum.r * v2.i + + sum.i * v2.r; + z__1.r = h__[i__4].r - z__2.r, z__1.i = h__[i__4].i - z__2.i; + h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; +/* L80: */ + } + +/* Apply G from the right to transform the columns of the */ +/* matrix in rows I1 to min(K+2,I). */ + +/* Computing MIN */ + i__3 = k + 2; + i__2 = min(i__3,i__); + for (j = i1; j <= i__2; ++j) { + i__3 = j + k * h_dim1; + z__2.r = t1.r * h__[i__3].r - t1.i * h__[i__3].i, z__2.i = + t1.r * h__[i__3].i + t1.i * h__[i__3].r; + i__4 = j + (k + 1) * h_dim1; + z__3.r = t2 * h__[i__4].r, z__3.i = t2 * h__[i__4].i; + z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; + sum.r = z__1.r, sum.i = z__1.i; + i__3 = j + k * h_dim1; + i__4 = j + k * h_dim1; + z__1.r = h__[i__4].r - sum.r, z__1.i = h__[i__4].i - sum.i; + h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; + i__3 = j + (k + 1) * h_dim1; + i__4 = j + (k + 1) * h_dim1; + d_cnjg(&z__3, &v2); + z__2.r = sum.r * z__3.r - sum.i * z__3.i, z__2.i = sum.r * + z__3.i + sum.i * z__3.r; + z__1.r = h__[i__4].r - z__2.r, z__1.i = h__[i__4].i - z__2.i; + h__[i__3].r = z__1.r, h__[i__3].i = z__1.i; +/* L90: */ + } + + if (*wantz) { + +/* Accumulate transformations in the matrix Z */ + + i__2 = *ihiz; + for (j = *iloz; j <= i__2; ++j) { + i__3 = j + k * z_dim1; + z__2.r = t1.r * z__[i__3].r - t1.i * z__[i__3].i, z__2.i = + t1.r * z__[i__3].i + t1.i * z__[i__3].r; + i__4 = j + (k + 1) * z_dim1; + z__3.r = t2 * z__[i__4].r, z__3.i = t2 * z__[i__4].i; + z__1.r = z__2.r + z__3.r, z__1.i = z__2.i + z__3.i; + sum.r = z__1.r, sum.i = z__1.i; + i__3 = j + k * z_dim1; + i__4 = j + k * z_dim1; + z__1.r = z__[i__4].r - sum.r, z__1.i = z__[i__4].i - + sum.i; + z__[i__3].r = z__1.r, z__[i__3].i = z__1.i; + i__3 = j + (k + 1) * z_dim1; + i__4 = j + (k + 1) * z_dim1; + d_cnjg(&z__3, &v2); + z__2.r = sum.r * z__3.r - sum.i * z__3.i, z__2.i = sum.r * + z__3.i + sum.i * z__3.r; + z__1.r = z__[i__4].r - z__2.r, z__1.i = z__[i__4].i - + z__2.i; + z__[i__3].r = z__1.r, z__[i__3].i = z__1.i; +/* L100: */ + } + } + + if (k == m && m > l) { + +/* If the QR step was started at row M > L because two */ +/* consecutive small subdiagonals were found, then extra */ +/* scaling must be performed to ensure that H(M,M-1) remains */ +/* real. */ + + z__1.r = 1. - t1.r, z__1.i = 0. - t1.i; + temp.r = z__1.r, temp.i = z__1.i; + d__1 = z_abs(&temp); + z__1.r = temp.r / d__1, z__1.i = temp.i / d__1; + temp.r = z__1.r, temp.i = z__1.i; + i__2 = m + 1 + m * h_dim1; + i__3 = m + 1 + m * h_dim1; + d_cnjg(&z__2, &temp); + z__1.r = h__[i__3].r * z__2.r - h__[i__3].i * z__2.i, z__1.i = + h__[i__3].r * z__2.i + h__[i__3].i * z__2.r; + h__[i__2].r = z__1.r, h__[i__2].i = z__1.i; + if (m + 2 <= i__) { + i__2 = m + 2 + (m + 1) * h_dim1; + i__3 = m + 2 + (m + 1) * h_dim1; + z__1.r = h__[i__3].r * temp.r - h__[i__3].i * temp.i, + z__1.i = h__[i__3].r * temp.i + h__[i__3].i * + temp.r; + h__[i__2].r = z__1.r, h__[i__2].i = z__1.i; + } + i__2 = i__; + for (j = m; j <= i__2; ++j) { + if (j != m + 1) { + if (i2 > j) { + i__3 = i2 - j; + zscal_(&i__3, &temp, &h__[j + (j + 1) * h_dim1], + ldh); + } + i__3 = j - i1; + d_cnjg(&z__1, &temp); + zscal_(&i__3, &z__1, &h__[i1 + j * h_dim1], &c__1); + if (*wantz) { + d_cnjg(&z__1, &temp); + zscal_(&nz, &z__1, &z__[*iloz + j * z_dim1], & + c__1); + } + } +/* L110: */ + } + } +/* L120: */ + } + +/* Ensure that H(I,I-1) is real. */ + + i__1 = i__ + (i__ - 1) * h_dim1; + temp.r = h__[i__1].r, temp.i = h__[i__1].i; + if (d_imag(&temp) != 0.) { + rtemp = z_abs(&temp); + i__1 = i__ + (i__ - 1) * h_dim1; + h__[i__1].r = rtemp, h__[i__1].i = 0.; + z__1.r = temp.r / rtemp, z__1.i = temp.i / rtemp; + temp.r = z__1.r, temp.i = z__1.i; + if (i2 > i__) { + i__1 = i2 - i__; + d_cnjg(&z__1, &temp); + zscal_(&i__1, &z__1, &h__[i__ + (i__ + 1) * h_dim1], ldh); + } + i__1 = i__ - i1; + zscal_(&i__1, &temp, &h__[i1 + i__ * h_dim1], &c__1); + if (*wantz) { + zscal_(&nz, &temp, &z__[*iloz + i__ * z_dim1], &c__1); + } + } + +/* L130: */ + } + +/* Failure to converge in remaining number of iterations */ + + *info = i__; + return 0; + +L140: + +/* H(I,I-1) is negligible: one eigenvalue has converged. */ + + i__1 = i__; + i__2 = i__ + i__ * h_dim1; + w[i__1].r = h__[i__2].r, w[i__1].i = h__[i__2].i; + +/* return to start of the main loop with new value of I. */ + + i__ = l - 1; + goto L30; + +L150: + return 0; + +/* End of ZLAHQR */ + +} /* zlahqr_ */ |